1. Field of the Invention
The present invention relates to a spare tire mounting structure for mounting fixedly a spare tire on cross members respectively interposed between a pair of side frames provided under the floor of the body of a vehicle through a hoist device and, in particular, to a spare tire mounting structure which is suitable for prevention of interference between a spare tire, a mounting bracket for mounting the same and the like, and peripheral devices when a collision occurs.
2. Related Art
As shown in FIG. 8, a spare tire 4 is disposed between a pair of side frames 23 under the floor of the rear portion of the body of a vehicle. The rear ends of the side frames and the rear portion of the spare tire 4 are disposed adjacently to the rear end of the vehicle and, therefore, when a collision occurs from behind the vehicle, a great forward shock is given to them. The spare tire 4 is generally held fixedly on the side frames 23 side by a mounting structure shown in FIG. 9. That is, between a pair of side frames 23 and 23, there are fixed a pair of front side and rear side cross members 24a and 25a in such a manner that they are properly spaced from each other in the longitudinal direction of the vehicle. A mounting bracket 30 is fixed to the front side cross member 24a and a canister 29 is fixedly held by the front side cross member 24a. The canister 29 is connected to a fuel tank (not shown) through a pipe or the like (not shown). By the way, the canister 29 is a device which adsorbs and stores a volatile fuel contained within the fuel tank and, generally, the outer plate of the canister 29 is formed of plastic material.
On the other hand, on the rear side cross member 25a, there is provided a hoist device mounting bracket 31 in such a manner that it is inclined forwardly with the base end side thereof fixed to the rear side cross member 25a. A spare tire hoist device 18a is mounted on the hoist device mounting bracket 31. The spare tire hoist device 18a comprises a securing member 20a, a chain 21a having one end side connected to the securing member 20a, a hoist member 19a for hoisting the chain 21a, and the like, while the hoist member 19a is fixed to the hoist device mounting bracket 31.
The spare tire 4 is fixedly held in such a manner that the front side of the outer periphery thereof is in contact with the mounting bracket 30 and the securing member 20a is secured to the disk wheel of the spare tire 4. By the way, as shown in FIG. 9, the spare tire 4 and hoist device mounting bracket 31 are arranged at a proper distance from the canister 29, so that they are prevented from interfering with each other.
On the other hand, conventionally, as a spare tire mounting structure, there are known a large number of structures and an example of such structures is disclosed in Unexamined Japanese Utility Model Publication Hei 4-55489, under the title of the invention "spare tire hoisting structure". The spare tire hoisting structure consists of a relatively simple structure in which a spare tire is fixed to one of a pair of cross members respectively provided between a pair of side frames of a vehicle, with the upper surface of the spare tire in contact with one of the two cross members.
However, in this structure, when a great external force is applied to the spare tire hoisting structure in a collision or the like, there is a possibility that the spare tire 4 can fall away from the cross member.
Also, in most of the other prior arts as well, unlike the present invention which will be described later herein, there is a possibility that a spare tire and the like can interfere with their peripheral devices in a collision.
As shown in FIG. 10, if a great external force F is applied to the conventional spare tire mounting structure having such a structure as shown in FIG. 9 in a collision or the like, then the spare tire 4 and side frames 23 are pushed forwardly and the rear side portion thereof is thereby deformed greatly. Due to such deformation, the spare tire 4 pulls strongly the chain 21a of the spare tire hoist device 18a in the downward direction. Also, due to such deformation, as shown in FIG. 10, the mounting bracket 30 is bent forwardly and the hoist device mounting bracket 31 is also deformed greatly in the forward direction, with the result that the hoist device mounting bracket 31 and spare tire 4 can interfere with the canister 29 to thereby deform the canister 29.